For a conventional semiconductor manufacturing apparatus for producing a silicon wafer, a processing and a treatment of a work such as an ion plating and a plasma etching have been carried out in a clean environment of a high vacuum, and a vacuum gate valve has been used in a gate opening part that is a taking part in and out of such a work.
For a semiconductor manufacturing apparatus that is shown in FIG. 11 for instance, a vacuum gate valve 104 is used to seal a gate opening part 110 that is configured for taking a wafer in and out between a process chamber 106 and a transfer chamber 108.
A seal plate 102 that is used in the vacuum gate valve 104 is made of a metal such as aluminum, and a seal member 100 is made of an elastic member such as a fluorine rubber.
In the case in which the gate opening part 110 is closed, the seal plate 102 is moved to a position which is opposed to a valve seat surface 112 of the gate opening part 110, the seal plate 102 is moved toward the gate opening part 110, and the seal member 100 of the seal plate 102 is made to come into contact with the valve seat surface 112 of the gate opening part 110 to seal the inside of the process chamber 106.
The seal plate that is configured as described above is configured by mounting a seal member 100a in a generally circular shape in a cross section into a groove 114 that has been formed on the outer edge part of a seal plate 102a as shown in FIG. 12. Moreover, the seal plate that is configured as described above is configured by bonding a seal member 100b in a generally rectangular shape in a cross section into a depressed part 116 that has been formed on the outer edge part of a seal plate 102b as shown in FIG. 13.
In the case in which the seal plates 102a and 102b that are configured as described above are used for a semiconductor manufacturing apparatus as described above in particular, the seal members 100a and 100b are exposed to a treatment gas such as a corrosive gas and an active gas that are used in the process chamber 106.
In the case in which the seal members 100a and 100b are exposed to such a treatment gas, a reaction occurs to deteriorate the sealability by slow degrees, and the sealability cannot be maintained for the last time.
In recent years, since an environment of usage for the seal plates 102a and 102b of the vacuum gate valve 104 has been severe, the seal members 100a and 100b that are made of a material that is provided with a more excellent plasma resistance have been used. However, the durability is not sufficient and a cost is higher in the present state of things.
Consequently, in the Patent Literature 1 as shown in FIG. 14, a groove 216 is formed at the position close to a gate opening part 210 of a seal plate 202 separately from a seal member 200 that has been mounted into a groove 214 of the outer edge part of a seal plate 202, and an auxiliary seal member 218 made of a fluorine resin that is provided with a resistance characteristic to a treatment gas is disposed in the groove 216 to configure a double seal structure what has been referred to as.
By configuring such a double seal structure, in the case in which the seal member 200 is made to come into contact with a valve seat surface 212 to carry out a sealing, the auxiliary seal member 218 comes into contact with the valve seat surface 212 and the seal member 200 can be prevented from being exposed to a treatment gas that is moved from the gate opening part 210.
Moreover, in the Patent Literature 2 as shown in FIG. 15, for a seal member 300 that has been mounted into a groove 314 of the outer edge part of a seal plate 302, the side close to the gate opening part 310 for the seal member 300 is covered by a substance such as a fluorine resin member 318 that is provided with a resistance characteristic to a treatment gas to configure a jacket seal structure what has been referred to as.
By configuring such a jacket seal structure, in the case in which the seal member 300 is made to come into contact with a valve seat surface 312 to carry out a sealing, the seal member 300 can be prevented from being exposed to a treatment gas that is moved from the gate opening part 310.